In the EAC, navigate to Mail flow > Send connectors, and then click Add .

In the New send connector wizard, specify a name for the send connector and then select Custom for the Type. You typically choose this selection when you want to route messages to computers not running Microsoft Exchange Server 2013. Click Next.

Choose Route mail through smart hosts, and then click Add . In the Add smart host window, specify the IP address, such as 192.168.100.1, or the fully qualified domain name (FQDN), such as contoso.com. Click Save.

For Smart host authentication, choose the type of authentication required by the smart host. If you choose Basic authentication, you must provide a user name and password.

Note:

If you choose Basic authentication, we recommend that you use an encrypted connection because the user name and password are sent in clear text.

Under Address space, click Add . In the Add domain window, make sure SMTP is listed as the Type. For Fully Qualified Domain Name (FQDN), enter * to specify that this send connector applies to messages sent to any domain. Click Save.

To verify that you have successfully created a Send connector to route outbound email through a smart host, send a message from a user in your organization (you can use the Outlook Web App) to the domain you specified for the Address space. If the recipient receives the message, you've successfully configured the send connector.